Variable Joint-Velocity Limits of Redundant Robot Manipulators Handled by Quadratic Programming

In this paper, a variable joint-velocity limits (VJVL)-constrained minimum-velocity-norm (MVN) scheme (termed VJVL-constrained MVN scheme) is proposed and investigated for redundant manipulators, i.e., the JVL change with the end-effector and joints movement. The scheme is then formulated as a quadratic program (QP), which is subject to an equality constraint and a bound constraint, and such a QP problem is solved by a discrete QP solver, i.e., a numerical algorithm. In addition, experimental results performed on a planar six degrees-of-freedom (6-DOF) push-rod (PR) redundant robot manipulator substantiate the physical realizability and efficacy of such a VJVL-constrained MVN scheme and the corresponding discrete QP solver. Furthermore, the position-error analyses verify the accuracy of the proposed scheme on redundant manipulators.